Award Bait Song: At least one per album: "To One in Paradise", "Don't Let It Show" (from I, Robot), "Day After Day", "The Eagle Will Rise Again", "If I Could Change Your Mind", "Time", "Old and Wise", "I Wouldn't Want To Be Like You" (from I, Robot)...
"Sirius" is arguably the Crowning Music amongst NBA fans, due to its use by the Chicago Bulls as their player intro music. Even if you're not a Bulls fan, you do recognize the music. Say it with me now: "Aaaaaaaaaaand now... the starting lineup... for your CHICAGO BULLS!"
Among fans, there seems to be general consensus that if Lenny Zakatek is singing on a track, it usually means the song in question is going to be good. Commonly cited evidence includes "I Wouldn't Want To Be Like You" (from I, Robot), "Games People Play" and "You Don't Believe".
Even some of their more obscure songs, such as "Can't Take it With You" and "La Sagrada Familia," are pretty epic.
Epic Riff: "(The System of) Dr. Tarr and Prof. Fether."
Also, "You're Gonna Get Your Fingers Burned."
As for non-guitar riffs, "I Robot", "Psychobabble", and "Standing On Higher Ground".
Face of the Band: Somewhat understandably, the Alan Parsons Project is often referred to as Alan Parsons's 'solo' career despite the equal contribution of singer/songwriter/keyboardist/bloke who came up with all the ideas for the concept albums Eric Woolfson. A fact somewhat underlined by all of the albums following Woolfson's departure being released under the sole name of Alan Parsons.
Genius Bonus: Or rather, Well-Traveled Bonus. The escalators in the cover art for I, Robot are those of Paris Charles DeGaulle Airport as it stood in the 1970s. (The escalators still exist, but you won't necessarily see them if you go through CDG; they're part of Terminal 1, which used to be the whole airport but is now something of a backwater, only operating flights for airlines not connected to Air France. It's rather a weird experience, whether or not you've seen the I Robot cover art.)
Tear Jerker: "Shadow Of A Lonely Man", the last track on "Pyramid", is particularly... depressing.